Carbon fibers are used to make composite materials. Such carbon composites provide the advantages of relatively high stiffness and strength, and low weight as compared to other materials commonly used to form articles such as automotive, boat, airplane and other parts. High stiffness and low weight are key advantages needed to reduce vehicle fuel consumption and increase fuel economy. The stiffness of the composite is directly related to the quality (graphitic nature) of the carbon fibers. Preferred fibers have basal planes arranged in concentric cylinders with respect to the fiber axis and are of microscopic size for improved stiffness-to-weight ratio. Such microscopic fibers effectively achieve the advantages of strength at a relatively low weight. When conventional materials are replaced with composite fiber materials, fuel economy is improved.
In U.S. Pat. No. 5,024,818, issued to the assignee of the present invention, Tibbetts et al described a new vertical reaction chamber and a new method for forming the fibers.
In pending U.S. application Ser. No. 07/709,259, Tibbetts et al described a new horizontal reaction chamber and still other new methods. These new methods and reactors improved fiber quality and improved production efficiency. However, it is desirable to achieve even better fiber quality and enhance production efficiency.